<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
        "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
    <title>边框</title>
  <style>
  #fun1{
  display:block;
   width:50px;
   height:100px;
   border:1px red solid;
  }
  </style>
</head>
<body>
    <span id="fun1">我是一个span</span>
</body>
</html>